Omega d5500 .. yellow not zeroing?

Wow I may finally be able to use my omega D5500 for the first time this weekend. It's been sitting for allmost 2 years.

I checked everything out tonight and it seems to be working.

Only problem I found is that when I hit the 'white' button, which is supposed to zero out all the colors, it gets stuck on yellow. I'm not totally sol though because when I manually set it to 0 yellow, it will eventually get there.

This worries me that the yellow filter will eventually freeze and the electronics wont know what to do..

Anyone have experience or advice?

You could try this memory clearall procedure. I used to use this on my D5500.
Not sure if it will zero filters out.
Press as follows -
1- FILTER
2- CAL + CANCEL
3- PRINT
4- CAL + HOLD
5- CAL + ENTER

Hope this is useful to you.

If the above does not work the gain on the Yellow could be off. The gain adjustment is on the color probe on the diffuser. The adjusters are continuously turning multi-turn trimmers. So, when you get to the end of the range they keep turning. The Yellow could be way out of adjustment. So, try turning the trimmer one way or the other and see if you can eventually get the motor to stop.

Of course when it stops , press "O" and then set the gain as close to zero as you can. I have a couple of diffuser boxes where the Yellow gain adjustment is very sensitive. (plus or minus 25 is ok by the manual)

Also, make sure the head is not off the enlarger and sitting on a colored surface.

Other things that I have run into that can cause difficulty in this area are having a rubber servo wheel overlap onto two filters and a loose setscrew on the rubber wheel.

If the motor keeps running it could also be that the rubber wheel has perished. I've uses tape with a little "tooth" on it around the shaft. It's trial and error though - enough tape to do the job and not enough to jam up the works! If you go this route though it becomes a regular maintenance routine.